In wireless communication field, in order to notify different parameters for transmission, different control information is sent from a transmit/receive point (TRP) to a user equipment (UE). Different control information may have different formats, which include one or more of different fields, different field orders, different bit lengths (also called payload sizes) for a same field, and other information. A format of control information, e.g., a downlink control information (DCI) format, may be involved for fallback. When a UE detects a format of control information for fallback, it needs to determine how to transmit or receive data and reference signals.